From d4a24eef7fd410c147de201d776089e0601317d5 Mon Sep 17 00:00:00 2001
From: Daniel <kingdread@gmx.de>
Date: Fri, 12 Jun 2020 00:48:18 +0200
Subject: initial work on comparison based filters

This enables filters such as
    -time > 2020-01-01
    -time < 2020-02-03
    ...
for time and duration, and later possibly also for more things (such as
a COUNT(...) construct).

This work tries to integrate them into the existing filter system as
seamless as possible, by providing a Comparator which implements
LogFilter.

The "type checking" is done at parse time, so nonsensical comparisons
like -time > 12s flat out give a parse error. This however might be
changed to a more dynamic system with run-time type checking, in which
case we could do away with the type parameter on Producer and simply
work with a generic Value. The comparator would then return an error if
two non-identical types would be compared.

Note that the system does not support arithmetic expressions, only
simple comparisons to constant values.
---
 src/fexpr/mod.rs | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'src/fexpr/mod.rs')

diff --git a/src/fexpr/mod.rs b/src/fexpr/mod.rs
index c6a3a39..1738e44 100644
--- a/src/fexpr/mod.rs
+++ b/src/fexpr/mod.rs
@@ -11,6 +11,9 @@ use itertools::Itertools;
 use lalrpop_util::{lalrpop_mod, lexer::Token, ParseError};
 use thiserror::Error;
 
+trait DateProducer = filters::values::Producer<Output = chrono::DateTime<chrono::Utc>>;
+trait DurationProducer = filters::values::Producer<Output = chrono::Duration>;
+
 lalrpop_mod!(#[allow(clippy::all)] pub grammar, "/fexpr/grammar.rs");
 
 #[derive(Debug)]
-- 
cgit v1.2.3


From e23af286b81f4c9df0e0ca9d71113caeb909cb0f Mon Sep 17 00:00:00 2001
From: Daniel <kingdread@gmx.de>
Date: Fri, 12 Jun 2020 13:21:35 +0200
Subject: implement count(player: ...) construct

---
 src/fexpr/mod.rs | 1 +
 1 file changed, 1 insertion(+)

(limited to 'src/fexpr/mod.rs')

diff --git a/src/fexpr/mod.rs b/src/fexpr/mod.rs
index 1738e44..f765acf 100644
--- a/src/fexpr/mod.rs
+++ b/src/fexpr/mod.rs
@@ -13,6 +13,7 @@ use thiserror::Error;
 
 trait DateProducer = filters::values::Producer<Output = chrono::DateTime<chrono::Utc>>;
 trait DurationProducer = filters::values::Producer<Output = chrono::Duration>;
+trait CountProducer = filters::values::Producer<Output = u8>;
 
 lalrpop_mod!(#[allow(clippy::all)] pub grammar, "/fexpr/grammar.rs");
 
-- 
cgit v1.2.3


From a8481afdac21b8b846d5fe159678972a879b11c0 Mon Sep 17 00:00:00 2001
From: Daniel <kingdread@gmx.de>
Date: Fri, 12 Jun 2020 13:44:19 +0200
Subject: add a comment about the trait aliases

---
 src/fexpr/mod.rs | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'src/fexpr/mod.rs')

diff --git a/src/fexpr/mod.rs b/src/fexpr/mod.rs
index f765acf..5d12051 100644
--- a/src/fexpr/mod.rs
+++ b/src/fexpr/mod.rs
@@ -11,6 +11,8 @@ use itertools::Itertools;
 use lalrpop_util::{lalrpop_mod, lexer::Token, ParseError};
 use thiserror::Error;
 
+// Lalrpop chokes on the associated type specification (it doesn't expect the =), so we need to
+// define those aliases here in Rust and then import and use them in the grammar.
 trait DateProducer = filters::values::Producer<Output = chrono::DateTime<chrono::Utc>>;
 trait DurationProducer = filters::values::Producer<Output = chrono::Duration>;
 trait CountProducer = filters::values::Producer<Output = u8>;
-- 
cgit v1.2.3